Crate kmp_embedded 

Embedded edition composition root (ADR-013): wires the application services over the local store with synchronous in-process projection, and resolves the data directory per the ADR-012 contract and the storage engine per ADR-018. No transport, no infrastructure clients.

Structs

BundleEventRange

Inclusive positions in the exported event stream. A full-store snapshot starts at one; an empty snapshot has neither bound.

BundleHeader

First line of a bundle file: identity and integrity metadata for fail-fast import. Fields added in bundle format 2 default only so format-1 bundles remain readable; every format-2 field is validated before replay.

CommitNativeBundle

The committed head bundle paired with the machine store it protects.

EmbeddedKernel

One opened embedded kernel: the composed service plus the store handle for operational tooling (replay, stats, compaction).

EmbeddedKernelStore

Every kernel persistence port on one local store.

PendingBundleExport

A marker intentionally has no cleanup in Drop: unwinding, a killed process, or an ambiguous backend error are precisely the cases that must remain visible to doctor.

StoreMigrationReceipt

What a migration did, kept in the store it produced.

Enums

ResolvedDataDir

Where the data directory came from — logged at startup so the winning resolution rule is always visible.

StorageEngine

The engine behind a data directory’s store/. Chosen once, when the directory is created; recorded as its FORMAT_VERSION; never guessed.

Constants

BUNDLE_FORMAT_VERSION

DATA_DIR_ENV

Explicit data directory override (ADR-012 rule 1).

ENGINE_ENV

Explicit engine override for a fresh data directory. Without it, the user-facing binary chooses SQLite when compiled and redb otherwise; existing directories always open from their stamp.

PENDING_EXPORT_DIR

PROJECT_BUNDLE_PATH

Where a project keeps the committed copy of its memory, relative to the project root.

SUPPORTED_FORMAT_VERSION

The layout this binary creates for a fresh data directory, and the one it has always created: redb (ADR-009).

Functions

clear_pending_bundle_exports

Clears markers after an operator has stopped other writers and explicitly acknowledged that a successful full export contains every committed write.

default_engine_for_data_dir

Implicit engine choice for a data directory when no operator override is present. Existing stores defer to their stamp; fresh stores prefer the shareable engine when this build carries it.

ensure_data_dir_skeleton

Creates the non-store part of a KMP data directory.

format_version_path

locate_data_dir_from_env

Resolves from the process environment and touches nothing.

merge_bundles

Merges only histories that have a deterministic answer: identical streams or one exact prefix of the other. Two branches that both appended at the same position are a semantic conflict, so KMP refuses to invent an order.

migrate_data_dir

Migrates source_dir into destination_dir, returning what was moved. The destination is created with the default engine.

migrate_data_dir_to

migrate_data_dir with the destination engine chosen — how a store changes engines (ADR-018). A redb store becomes a SQLite one that two agent hosts can share by replaying its history into a fresh directory; the source stays as it was and the receipt records both layouts.

open_or_migrate_data_dir

Migrate once, reopen afterwards. Safe on every start: a destination that already holds a store is opened as it is, and the returned receipt says whether this call was the one that migrated it.

parse_engine

Parses an engine name the way the environment variable and the CLI spell it. Pure, for testing; resolve_engine_from_env feeds it.

pending_bundle_exports

project_bundle_path

The conventional bundle path for the project data_dir belongs to.

read_stamped_version

The version stamped in data_dir, without applying the gate.

resolve_data_dir

ADR-012 resolution: env override > project .kernel/ > per-user default. Pure function for testability; resolve_data_dir_from_env feeds it from the process environment.

resolve_data_dir_from_env

Resolves from the process environment and prepares the directory. Every data directory gets the same safety skeleton, regardless of whether it was discovered from a project, supplied explicitly, or created by migration.

resolve_engine_for_data_dir_from_env

Resolves the engine for a particular data directory.

resolve_engine_from_env

The engine KMP_MCP_ENGINE asks for, if it is set. Unset or empty means “no preference”: a fresh directory gets the default, an existing one opens as it is.

store_file_path_for

Where engine keeps its store inside data_dir.

user_data_home

Where user-scope memory lives: $XDG_DATA_HOME, or ~/.local/share.

verify_bundle

Validates a bundle without opening or mutating a store. This is the recovery check: identity, range, about coverage and digest are all proved before an operator trusts a saved copy.

write_bundle_atomically

Same-directory durable replacement, so a failed export leaves either the previous complete bundle or the next complete bundle, never half a JSONL stream. Unix rename replaces atomically; Windows keeps the previous file beside it until the new one has taken the canonical name.

write_bundle_if_absent

Publishes an immutable bundle without a check-then-replace race. The hard link is an atomic create-if-absent operation on the same filesystem: two snapshot creators can agree on existing content, but neither can replace the other’s recovery point.

Type Aliases

EmbeddedMemoryService

The KMP memory facade composed over the embedded store: every port is the same single-file redb store, and ingest projects synchronously in-process, which is what makes read_after_write_ready unconditionally true.